Erecting device for gyroscopes



Jan. 20, 1953 G, AGlNs 2,625,825

ERECTING DEVICE FOR GYROSCOPES Filed March 8, 1951 GEORGE AGINS wwf@ TOE N EY type and the like.

Patented Jan. 20, 1953 UNITED STATES PATENT OFFICE ERECTING DEVICE FOR GYROSCOPES George Agins, Santa Monica, Calif., assignor to Arma Corporation, Brooklyn, N. Y., a corporation of New York ApplicationfMarch 8, 1951, Serial No. 214,614

. means therefor.

Various types of gravity erection means are familiar to those in the art including rolling ball All of these prior methods are designed to produce a phase difference between` the plane of tilt of the gyro spin axis and the plane in which the erecting force is applied,` whence the gyro spin axis erects into the true vertical. ally these methods seek to provide is 90 so that The optimum phase difference which the erection of the spin axis is accomplished in the shortest time, directly into the vertical. Phase differences other than 90 also eifect erection into the vertical, but along the familiar spiral course.

In the present invention a mechanical system, which isv tuned to a natural frequency proportional to the nominal rotational velocity of the gyroscope rotor, is driven by one of the rotor shafts. A tially of a vertically disposed mechanical reed The mechanical system consists essenwhich carries a weight on its free end and is secured to a rotating shaft at its fixed end.

AWhen the spin axis of the gyro is tilted out of the true vertical, the weight on the reed causes` a varying disturbing force to be applied to the reed in its plane of vibration to thereby force the reed to vibrate at a frequency at or near its natural frequency. The reed therefore experiences a maximum deflection out of phase with the planev of tilt and has a mean effective `position approximately half-way between the panying diagrams, in which,

Fig. 1 is a cross sectional view taken on line I-I of Fig. 3, looking in the direction of the arrows, of a gyroscope embodying the present invention,

Fig. 2 is a section through line 2--2 of Fig. 1,

looking in the direction of the arrows, and

Fig. 3 is a section through line 3-3 of Fig. 1, looking in the direction of the arrows.

Figure l is a schematic representation of a vertical section through a three axis of freedom vertical spin axis gyroscpe embodying the present invention. The gyro rotor I0 is supported within casing II by the upper and lower shafts I2 and I3 respectively journalled in their respective bearings I2' and I3', and is preferably driven by electrical inductive reaction with the energized winding 26. Casing II is supported by horizontal shafts I5 and I6 journalled within bearings I5 and I6 held within the gimbal 'ring I4, which is in turn supported by horizontal shafts (not shown) perpendicular to shafts I5 and I6 journalled within the supporting frame I1.

The upper shaft I2 of the rotor I0 is terminated in a Worm gear I8 which drives the shaft I9 and Worm gear 20 by means of the meshing gear 2 I. Worm gear 20 drives gear 22 and thereby drives shaft 23. Extending vertically upward from shaft '23 is the mechanical reed 24 which carries the weight 25 on its free end. Although the reed is shown as extending upward, the gears I8, 20, 2| and 22 may alternatively be driven by shaft I3, with reed 24 hanging downward, if desired, without affecting the operation of the invention. The weight 25 is preferably of magnetic and electrically conducting material for damping purposes as will be explained later. The weight W is provided in order to compensate for the static unbalance produced by the weight of gears 20, 2l, '22, shafts I9 and 23 and of reed 24 and its weight 25 as a result of their displacement from the suspension axes of case II.

In operation, rotation of the gyro wheel I0 causes rotation of shaftv 23 and reed 24. When the gyro spin axis is tilted out of the vertical, the axis of rotation of reed 24 is similarly displaced from the vertical and the weight 25ap- 'plies a bending force to the reed 24. Rotation of reed 24 causes the resistance to bending to vary periodically as the plane of the reed rotates s0 that a periodic force is applied to the reed 24 which forces the reed 24 into vibration.

If the reed 24 is proportioned so that its dynamic natural frequency, that is, its natural frequency while rotating, corresponds to the nominal rotational speed of the shaft 23 (proportional to the speed of wheel I0) then the condition of resonance is achieved and the maximum deflection of reed 24 occurs out of phase with the application of the maximum bending force, with the deflection lagging the force. The

static natural frequency of reed 24 must be \/2w in order that the dynamic natural frequency of reed 24 will be w when rotating at a speed w.

Assume forexample that'in Fig. 1 the top of the gyro spin axis is tilted out of the plane of the drawing, i. e. toward the observer, and that the gyro wheel la is rotating in the direction of the arrow. The gearing between rotor I and shaft 23 is such that shaft 23 rotates in the same direction as the rotor lll. Thus, as shaft 23 rotates and the top of the gyro is tilted toward the observer, the reed 2d experiences a maximum deflection to the right in Fig. l, assuming the condition or" resonanceto apply. Ity will be seen that during eachrrevolution of shaft23 the weight 25 undergoes two cycles of displacement to the right, and has an average or effective position halfway between the maximum displacement and the gyro spin axis.

Thus, the position of .weight 25 produces a weight unbalance and causes a torque to be applied to the gyro such that the top of the spin axis is urged to the right thereby causing vprecession of the top of the gyro spin axis into the plane of the drawing Fig. 1 and therefore causing erection of the spin axis into the true vertical. The magnitude of the vibration of reed r2| is proportional to the tilt of the axis of rotation from the vertical, whence the erection rate of thespin axis is proportional to the deviation of the, spin axis from the true vertical.

For ease of description it has been assumed that the ideal condition of resonance of reed 24 is attained during the operation of this invention. In the usual case, however, the speed of Wheel l0. cannotbe maintained at the exact speed requiredto turn shaft '23 at the speed for which reed, Zllis resonant. Then, instead of the ninety .degreephase lag between the bending force and deflection of reed 24, the phase angle is less than 90 Vfor slower speeds and more than 90 for higher speeds. Nevertheless, it will be seen that the. gyro spin axis follows the familiar spiral route,.as erectioninto the true vertical is accomplshed.

Variable viscous damping of the vibration of reed. 24 .is provided by the magnetized slug 21 which is threaded incasing directly over the shaft 23 and weight 25.

The distance of the lowerface of slug 21 from the top of reed 24 may be varied'by rotatingv the slug '2.1, thus varying the strength of the magnetic eld in which effecting. the viscous, damping,r of .thereed 2 4.

Provision isv made yfor reducing .the effects 'of' acceleration, forces on Vweight 2.5 during changes Hof` speed or course of the vehicle carrying the compass by energizing the Vcoil 28 by the full voltage of power supply '29 which effectively stiens reed 24 during such changes. Switch V3|, connected across resistor 30, is essentially ycomposed of a stationary contact 32 in the form `of a ring which surrounds a` pendulous movable contact 33.v When the rate of change in speed -or .course is sufficient to cause `the pendulous contact .33 to swing into cooperation with ring v32, .switch 3| short circuits resistor 30 so that .coil 28 is energized directly by power supply 29.

The magnetic eld thus produced attracts the weight .25 and thus stiffens the reed 24 to minimize the displacement of Weight 25 by the accel'eration4 force. It should be realized that for properv operation switch 3| must be mounted in a .stabilized position which may be on case of the gyroscope for example, or on a platform stabilized by the gyroscope in the usual manner which will not be described here. Also, to prevent locking of the system when attempting to put the gyro into operation from a tilted position switch 3| must be disconnected from the circuit during starting periods. To this end switch 3dl is-provided and is left open until the gyroscope isr in the normal operating position when the spin axis is vertical.

Although a preferred embodiment of the invention has been illustrated and described herein, it is to be understood that it is by way of illustration only and that the invention is not limited thereby, but is susceptible of changes in form rand detail'within the scope of the appended claimsJ I claim:

1. In an erection system for gyroscopes, a

Vvertical disposed reed, said reed being secured adjacent one end to a rotating shaft and.` carrying a weight adjacent its free end.

2. In an erection systemfor gyroscopes, avertically disposed reed, said reed being securedad- `jacent one end to arotating shaft and carrying a weight adjacent its opposite end and means cooperating with said weight for variabler damping of the vibration of' said reed.

3. In an erection system for gyroscopes, a vertically disposed reed, said reed being secured to a rotating shaft and carrying a weightadjacent its free end, said weight being of electrically conducting material and electrical meansvcooperating with said weight for variable damping of the vibration of said reed.

4. In an erection system for gyroscopes, avertically disposed reed, said reed beingsecured adjacent one end to a rotating shaft and carrying a weight member adjacent its free end', means for effecting variable damping of the vibration of said reed, said means comprising a member adapted to cooperatively function with said weight, one of saidv members having magnetic means adapted'to effect damping-of thevibration of .said reed.

5. In an erecting system .for gyroscopes, a vertically disposed reed, said reed being Asecured adjacent one end to a rotating shaft and carrying a weight member adjacent its free end, means Yfor effecting variable damping of the vibration of said reed, said means comprising a member adapted to cooperatively function with said weight, one of saidY members havingy magnetic means to effect damping ofthe vibration of 'said reed and means for-varying the strength lofsaid magnetic means.

'6. In an erection system for gyroscopes,'a vertically disposed reed, said reed being secured adjacent one end to a rotating shaft and carrying a weight member adjacent its free end, means Vfor eifecting variable damping ofv the vibration of said reed, said means comprising a member adapted to cooperatively `functionY with said Weight member, one of 'said members having magneticmeans adapted to Yeffect damping of the vibration of said reed and a variable resistor for varying the strength of said magnetic means.

'7. In an erection system forgyroscopes, avertically disposed reed, said reed being secured. to a rotating shaft and carrying a weight adjacent'its free end,v said weight being ofV electrically conducting material and electrical'means Afor creating a. magnetic eld adjacent said weight and adapted to cooperatively function with said weight to effect viscous damping of the vibration of said reed.

8. In an erection system for gyroscopes, a ver-tically disposed reed, said reed being secured to a rotating shaft and carrying a weight adjacent its free end, said weight being of electrically conducting material and electrical means for creating a magnetic field adjacent said Weight and adapted to cooperatively function with said weight to eiect viscous damping of the vibration of said reed and means whereby the strength of said magnetic field may be varied.

9. In an erection system for gyroscopes, a vertically disposed reed, said reed being secured to a rotating shaft and carrying a Weight adjacent its free end, said weight being of electrically conducting material and electrical means for creating a magnetic field adjacent said weight and adapted to cooperatively function with said weight to effect viscous damping of the vibration of said reed and a variable resistor for varying the strength of said magnetic field.

10. In an erection system for gyroscopes, a vertically disposed reed, said reed being secured to a rotating shaft and carrying a Weight adjacent its free end, said weight being of electrically conducting material and electrical means for creating a magnetic eld adjacent said weight and adapted to cooperatively function with said weight to effect viscous damping of the vibration of said reed, said electrical means being adjustable relative to said Weight.

11. In an erection system for gyroscopes, a vertically disposed reed, said reed being secured to a rotating shaft and carrying a Weight adjacent its free end, said weight being of electrically conducting material and electrical means for creating a magnetic field adjacent said Weight and adapted to cooperatively function with said Weight to effect viscous damping of the vibration of said reed, said electrical means comprising a magnetized member which is adjustable relative to said weight.

" GEORGEA AGIN S.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,984,859 Bates Dec. 18, 1934 2,274,443 Fischer 1 Feb. 24, 1942 2,480,263 Raspet Aug. 30, 1949 2,510,068 Carter June 6, 1950 2,511,178 Roters June 13, 1950 

